Adult: Species description based on Savage (2002). A medium-sized treefrog (males to 34 mm, females to 37 mm). Dorsal: The dorsal coloration varies from grey to light brown. Some darker markings are usually, but not always, present. Most individuals have a thin, dark line running through (present on either side of) the eye. The sides are usually yellowish, but the sides of some individuals appear greenish or bluish. Ventral: The ventral surface is cream-colored or yellowish with extensive brown or black flecking. Eye: The iris is bronze with black reticulations.
Breeding season: Males call from vegetation along the margins of streams throughout the year (Savage 2002). Breeding likely occurs year-round (Duellman 1970), but seems to peak at the beginning of the rainy season (Savage 2002). However, reproduction has not been observed (Savage 2002). Egg: Gravid females contain 76-104 eggs (Lang 1995). Tadpole: The tadpole is oval shaped, but somewhat compressed dorsally (Savage 2002). Tadpoles are brown with some gold flecking apparent (Savage 2002). The tail is light brown, with extensive dark blotching along the top and less pigmentation extending down onto the sides of the tail (Savage 2002). Tadpoles have a large suctioncup-like mouth that enables them to adhere to rock surfaces in fast-moving streams (Savage 2002).
Habitat: Premontane and lower montane forest (1210-2040 m). Call: A series of three "cheeps" (Savage 2002). Karyotype: 2N = 24 (Leon-Azofeifa 1970) Type locality: American Cinchona Plantation (Isla Bonita), eastern slope of Volcán Poás, Costa Rica, elevation 5,500 ft